Semboku weather in August

In August, Semboku sees average daytime highs of 25°C and overnight lows near 19°C, with 216 mm of rain across 17.9 wet days and about 13.6 hours of daylight. It is the 1st-warmest and 2nd-wettest month of the year here.

Day-to-day highs hold fairly steady near 25°C through the month. The sky is clear or mostly clear about 15% of the time in August, and the air most often feels muggy.

Daylight stretches from about 14 h 06 min at the start of August to 13 hours by month's end. Set against the rest of the year, August is Semboku's 7th-clearest and 11th-windiest month. For the whole year in context, see Semboku's year-round climate.

Daytime high
25°
1st warmest
Overnight low
19°
12th coldest
Rainfall
216 mm
17.9 wet days
Daylight
13 h 36 min
4:54 AM – 6:28 PM
Cloud cover
74%
7th clearest
Wind
6 km/h
11th windiest
Solar energy
4.32 kWh/m²
Travel score
5.4
out of 10

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 25°C through the month.

A typical August day in Semboku reaches about 25°C in the afternoon and slips back to 19°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 29°C. Set against its neighbours, August runs about 1°C warmer than July and about 4°C warmer than September.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12619
22619
32619
42619
52619
62619
72619
82619
92619
102619
112619
122619
132619
142619
152519
162519
172519
182519
192519
202519
212518
222518
232518
242518
252518
262518
272518
282418
292418
302417
312417

How August really feels in Semboku

Once humidity and wind are folded in, August averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

August sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Semboku weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-1° / -8°10718.322.19.50.0
Feb / -7°9816.118.310.40.0
Mar / -4°13418.316.211.70.1
Apr10° / 13315.95132.1
May17° / 150150.114.24.6
Jun21° / 13°15815.1014.85.3
Jul24° / 18°25019.6014.55.2
Aug25° / 19°21617.9013.65.4
Sep21° / 14°18715.8012.35.4
Oct15° / 159150.310.94.1
Nov / 13717.66.49.81.2
Dec / -5°13019.419.29.20.0

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 15% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 12% of August, with mostly cloudy or overcast conditions the remaining 73%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
12773
22872
32872
42773
52773
62872
72872
82872
92773
102674
112674
122773
132674
142674
152674
162674
172674
182773
192773
202773
212872
222773
232773
242773
252674
262674
272674
282773
292674
302674
312674

Chance of precipitation in August

Any precipitation

Semboku gets around 216 mm of rain over 17.9 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 57% and peaks near 59% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
155
255
355
455
556
656
756
856
956
1056
1156
1257
1357
1457
1558
1658
1758
1858
1958
2058
2158
2258
2359
2459
2559
2659
2759
2858
2958
3058
3158

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

Most of August feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, August lands in the muggy band about 46% of days. Sticky, muggy-or-worse air turns up on roughly 63% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
117195617
218185518
318185518
418185419
518185419
618185419
718185320
819185220
919195120
1019195120
1119205020
1219214920
1319214920
1419224820
1519234720
1629244619
17210244519
18210254518
19310254418
20311264317
21311274216
22412274115
23413284115
24413294014
25514293913
26514303912
27515313811
28516323710
2951733369
3061734359
3161834338

Wind in August

Winds average 6 km/h in August.

Across August, daily wind ranges from about 6 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 06 min at the start of August to 13 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over August. Sunrise moves from 4:40 AM to 5:08 AM, and sunset from 6:47 PM to 6:06 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.14:406:47
214.14:416:46
314.14:416:44
414.04:426:43
514.04:436:42
613.94:446:41
713.94:456:40
813.94:466:39
913.84:476:38
1013.84:486:36
1113.84:496:35
1213.74:506:34
1313.74:516:32
1413.74:526:31
1513.64:536:30
1613.64:546:28
1713.54:556:27
1813.54:566:26
1913.54:576:24
2013.44:586:23
2113.44:596:21
2213.35:006:20
2313.35:016:18
2413.35:026:17
2513.25:036:15
2613.25:036:14
2713.15:046:12
2813.15:056:11
2913.05:066:09
3013.05:076:07
3113.05:086:06

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.32 kWh/m².

For context, solar energy here swings from a low near 1.73 kWh/m² to a high of 5.22 kWh/m² in May across the year — August's 4.32 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.6Bright
24.6Bright
34.6Bright
44.6Bright
54.6Bright
64.6Bright
74.6Bright
84.5Bright
94.5Bright
104.5Bright
114.5Bright
124.4Bright
134.4Bright
144.4Bright
154.3Bright
164.3Bright
174.3Bright
184.2Bright
194.2Bright
204.2Bright
214.2Bright
224.1Bright
234.1Bright
244.1Bright
254.1Bright
264.0Bright
274.0Bright
284.0Bright
294.0Moderate
304.0Moderate
313.9Moderate
Planning a trip in August

Is August a good time to visit Semboku?

Our two travel scores rate August for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

5.4
Sightseeing
1st-best month of the year
5.0
Beach & pool
1st-best month of the year

August is a reasonable time to visit Semboku for sightseeing.

What to pack for Semboku in August

From August's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In August, Semboku sees daytime highs around 25°C and nights near 19°C. Pack rain gear. Worth having: light clothes. About 18 days see rain.

rain gearlight clothes

UV index in Semboku in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Semboku peaks around August 18 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighVery highHighModerateLowAug 18UV 9Jan 1UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun8Very high
Jul6High
Aug9Very high
Sep7High
Oct5Moderate
Nov2Moderate
Dec2Low

Air quality in Semboku in August

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where August falls, not just the annual average.

Air quality in Semboku is worst in April — around 20 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (December, 9 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1420 µg/m³Dec 1610 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar19Moderate
Apr20Moderate
May19Moderate
Jun14Moderate
Jul12Moderate
Aug11Good
Sep11Good
Oct12Good
Nov11Good
Dec9Good
Location & terrain

Where is Semboku?

Semboku sits at 39.7°N, 140.7°E, 389 m above sea level, in Japan. The nearest listed city is Shizukuishi, 20 km away.

Topography around Semboku

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Semboku.

Within 3 km, the terrain around Semboku has large variations in elevation — a maximum elevation change of 836 m around an average of 444 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,556 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,976 m.

The land around Semboku is covered by trees (88%) within 3 km, trees (91%) within 16 km, and trees (80%) within 80 km.

3 km
836 m
16 km
1,556 m
80 km
1,976 m
treesgrasslandcroplandartificial surfaceswater
August weather nearby: Shizukuishi 20 km · Morioka 35 km · Takizawa 35 km · Yahaba 36 km · Ōmagari 37 km · Rokugō 37 km · Daisen 37 km · Hachimantai 39 km

Japan travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B
100 V · 50 / 60 Hz
Prices
≈ 65% of US
price level, 2025
GDP per capita
$35,951
2025
Happiness
6.1 / 10
World Happiness, 2025
Safe drinking water
99%
of population, 2024
Homicide rate
0.2
per 100k, 2023
Road deaths
3.6
per 100k/yr, 2019
Income group
High
World Bank
English
Very low
EF EPI 446
Religion
Shintoism 49%Buddhism 46%other 4%Christianity 1%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Semboku (39.7093°, 140.7465°, elevation 389 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).